TorqueScreen: Haptic Feedback On-the-Go

January 26, 2015 by Sonya Vasquez 9 Comments

If you’ve been keeping your skills fresh with any console video games in the last 15 years (or you’ve acquired a smartphone), you’ll know that “rumble,” or “haptic” feedback plays a key role in augmenting our onscreen (or touch-screen typing) experience. Nevertheless, this sort of rumble feedback is surprisingly boolean, and hasn’t developed into a richer level of precision since it started to be introduced in gaming over 30 years ago. In response, [Martin] and his fellow design teammates at the University of Salzburg, Austria have introduced the TorqueScreen, a mobile haptic attachment that puts a twist on conventional force feedback.

At its core the TorqueScreen is a gyroscope attached to a servo with the respective rotational axes in a perpendicular alignment. When the servo rotates the live gyroscope, the user can sense the tablet’s resistance to rotate about the servos axis.

The team’s conference demonstration model features a brushless motor plucked from an old hard drive controlled by an Arduino and driven manually by a Wii nunchuck. Currently only one rotational axis resists changes in rotation, but a gimbal may be the next step in this project.

We’ve certainly seen budget handheld haptic devices before, but this project allows for an entire spread of responses proportional to the speed at which the gyroscope is rotated about the servo axis.

Unless you’re reading this post on your already-torquescreen-enabled mobile device, it’s a bit difficult to get a feel for what kind of interactions you can produce with this setup. The video (after the break), though, can give you a pretty good idea of what kind of interactivity you’d expect with device clipped onto your tablet.

[via the Tangible, Embedded, and Embodied Interaction Conference]

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Audience Pong And RC Trash Bins: An Intro To TEI

January 24, 2015 by Sonya Vasquez 2 Comments

This past weekend, I had the chance to visit this year’s Tangible, Embedded, and Embodied Interaction Conference (TEI) and catch up with a number of designers in the human-computer-interaction space. The conference brings together a unique collection of artists, computer scientists, industrial designers, and grad students to discuss computer interactivity in today’s world. Over the span of five days (two for workshops, and three for paper presentations), not only did I witness a number of today’s current models for computer interactivity (haptics, physical computing with sensors), I also witnessed a number of excellent projects: some developed just to prove a concept, others, to present a well-refined system or workflow. It’s hard to believe, but our computer mouse has sat beneath our fingertips since 1963; this conference is the first place I would start looking to find new ways of “mousing” with tomorrow’s technology.

Over the next few days, I’ll be shedding more light on a few projects from TEI. (Some have already seen the light of day.) For this first post, though, I decided to highlight two projects tied directly to the conference culture itself.

Before each lunch break, the audience was invited to take part in an audience-driven interactive game of “Collective” Pong. With some image processing running in the background, players held up pink cards to increase the height of their respective paddle–albeit by a miniscule amount. The audience member’s corresponding paddle weight was mapped to their respective marker location on the screen (left or right). It turns out that this trick is a respectful nod back to its original performance by [Loren Carpenter] at Siggraph in 1991. With each audience member performing their own visual servoing to bring the paddle to the right height, we were able to give the ball a good whack for 15 minutes while lunch was being prepared.

Next off, the conference’s interactivity spread far beyond the main conference room. During our lunch breaks we had the pleasure of discarding our scraps in a remotely operated trash bin. Happily accepting our refuse, this bin did a quick jiggle when users placed items inside. Upon closer inspection, a Roomba and Logitech camera gave it’s master a way of navigating the environment from inside some remote secret lair.

Overall, the conference was an excellent opportunity to explore the design space of tinkerers constantly re-imagining the idea of how we interact with today’s computers and data. Stay tuned for more upcoming projects on their way. If you’re curious for more details on the papers presented or layout of the conference, have a look at this year’s website.

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Open Source Haptics Kit Aims To Democratize Force Feedback

January 21, 2015 by Sonya Vasquez 27 Comments

If you’ve been keeping up with augmented and virtual reality news, you’ll remember that spacial haptic feedback devices aren’t groundbreaking new technology. You’ll also remember, however, that a professional system is notoriously expensive–on the order of several thousand dollars. Grad students [Jonas], [Michael], and [Jordi] and their professor [Eva-Lotta] form the design team aiming to bridge that hefty price gap by providing you with a design that you can build at home.

A quick terminology dive: a spacial haptic device is a physical manipulator that enables exploration of a virtual space through force feedback. A user grips the “manipulandum” (the handle) and moves it within the work area defined by the physical design of the device. Spacial Haptic Devices have been around for years and serve as excellent tools for telling their users (surgeons) what something (tumor) “feels like.”

In our case, this haptic device is a two-link, two-joint system grounded on a base station and providing force feedback with servo motors and tensioned wire ropes. The manipulator itself supports 3-degree-of-freedom movement of the end-effector (translations, but no rotations) which is tracked with encoders placed on all joints. To enable feedback, joints are engaged with cable-drive transmissions.

The design team isn’t new to iterative prototyping. Hailing from CS235, a Stanford course aimed to impart protoyping techniques to otherwise non-tinkerers, the designers have drawn numerous techniques from this course to deliver a fully functional and reproducible setup. In fact, it’s clear that the designers have a strong understanding of their system’s physics, and they capitalize on a few tricks that don’t immediately jump out to us as intuitive. For instance, rather than rigidly fixing their cable to the motor shaft, they simply wrap the cable around the shaft a mere 5 turns such that the force of friction greatly exceeds the threshold amount that would otherwise cause slipping. They also choose plywood–not necessarily because of its price–but more so because of its function as a stiff, layered composite that makes it ideal “lever arm material” for rigidly transferring forces.

For a full breakdown of their design, take a look at their conference paper (PDF) where they evaluate their design techniques and outline the forward kinematics. They’ve also provided a staggeringly comprehensive bill of materials (Google Spreadsheet). Finally, as justifiably open source hardware, they’ve packaged their control software and CAD models into a github repository so that you too can jump into the world of quality force feedback simulation without shelling out the twenty thousand dollars for a professional system.

[via the 2015 Tangible Embedded and Embodied Conference]

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Spliced Animations Come To Life On Their Pages

January 16, 2015 by Sonya Vasquez 15 Comments

Remember those flipbooks you doodled into your history textbooks while you waited for the lunch bell? [Maric] takes the general principles of flipbooks and turns them on their head, giving our brain a whirl in the process. By splicing multiple frames into one image, he can bring animations to life onto a single page.

The technique is simple, but yields impressive results. By overlaying a pattern of vertical black bars onto his image, only a small fraction of the image is visible at any given point. The gaps in the pattern belong to a single frame from the animation. As [Maric] slides the pattern over the image, subsequent frames are revealed to our eyes, and our brain fills in the rest.

A closer look reveals more detail about the constraints imposed on these animations. In this case, the number of frames per animation loop is given by the widths in the transparency pattern. Specifically, it is the number of transparent slits that could fit, side-by-side, within an adjacent black rectangle.

The trick that makes this demonstration work so nicely is that the animated clips finish where they start, resulting in a clean, continuous illusion.

Don’t believe what you see? [Maric] has linked the pattern and images on his video so you can try them for yourself. Give them a go, and let us know what you think in the comments.

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Budget Wrist-Controlled RC Car Is A Nice Touch

January 15, 2015 by Sonya Vasquez 2 Comments

Does your RC car’s crude, push-button controller make you feel like you’re mashing tv remote buttons like a caveman? We think so too, but [Noel] has actually done the heavy-lifting to fix just that. He’s revamped his kids’ rc controller for gesture control. Now their rc car can be guided by the crisp, intuitive control of one’s wrist movements.

To tackle this project, [Noel] has integrated a gyroscope and accelerometer, an Arduino, and the existing remote. Data from the gyroscope-and-accelerometer limits are mapped to the buttons through an Arduino, which parses the raw data and triggers the controller’s switches, now wired directly to the Arduino and pulled up with resistors. In his overview video, [Noel] tells us that he’s binarized the gyroscope-and-accel data to trigger at certain limits, a choice that adequately suits the controller’s original push-button controls. Finally, the entire setup is cleanly strapped to a 3D-printed case. Not bad, for a grand total of $20 and a quick trip to Target.

[Noel]’s custom wrist-controller takes its place on the shelf of many other unique controllers, and his demo is a great example of using existing open hardware to tailor our toys to more personal tastes. After all, the hardware shopping list is just a breakout board, an Arduino, and a few jumper wires. When the next zombie apocalypse hits, we can easily see some practical components like these making their way into our suitcase. At the very least, we’ll be able to build a few wrist controllers and dispatch some toy cars to greet the undead.

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3D Printing RC Airplanes That Fly: An Engineer’s Chronicle

January 5, 2015 by Sonya Vasquez 14 Comments

In the past, creating accurate replicas of models and fantasy objects was a task left to the most talented of cosplayers. These props need not be functional, though. [Steve Johnstone] takes replica model-building to the next step. He’s designing and building a model airplane that flies, and he’s documenting every step of the way.

Armed with a variety of 3D printing techniques and years of model-building experience, [Steve] is taking the lid off a number of previously undocumented techniques, many of which are especially relevant to the model-builder equipped with a 3D printer in the workshop.

As he continues his video log, [Steve] takes you through each detail, evaluating the quality of both his tools and techniques. How does a Makerbot, a Formlabs, and a Shapeways print stand up against being used in the target application? [Steve] evaluates a number of his turbine prints with a rigorous variable-controlled test setup.

How can we predict the plane’s center-of-gravity before committing to a physical design? [Steve] discusses related design decisions with an in-depth exploration of his CAD design, modeled down to the battery-pack wires. Though he’s not entirely finished, [Steve’s] work serves as a great chance to “dive into the mind of the engineer,” a rare opportunity when we usually discover a project after it’s been sealed from the outside.

3D printing functional parts with hobbyist-grade printers is still a rare sight, though we’ve seen a few pleasant and surprisingly practical components. With some tips from [Steve], we may complete this video journey with a few techniques that bump us out of the “novelty” realm and into a space where we too can start reliably printing functional parts. We’re looking forward to seeing the maiden voyage.

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Skyscraper Tetris Lets The City Know How Good Or Bad You Are

January 1, 2015 by Sonya Vasquez 16 Comments

If you’ve clocked one-too-many hours at Tetris, it might be time to show the world your skills on this skyscraper-sized display on the Shell Centre in London. [Benjamin], [Tom], and their “army of volunteers” took to the Shell building and assembled their super-screen from a collection of 182 networked wireless lightbulbs, some tracing paper, and mylar to create a playable interface from the Jubilee Gardens below.

[Benjamin] doesn’t deliver many of the technical details on his post, but he does give us an overview. He achieves full wireless coverage of all floors by spacing out 14 TP-Link WR702n routers, each running the same version of OpenWRT. This interface wasn’t [Benjamin’s] first choice, as he would’ve preferred to tap into the building’s existing wireless network; unfortunately, he was left without support from the building’s network team. Equipped with a large donation of wireless bulbs controlled by a central bridge, [Benjamin’s] Python-adaptation of Tetris can refresh the building about about 1-to-2 frames per second. Given his description of the bulb interface, we suspect he’s using the all-too-familiar Philips Hue smart lightbulbs to illuminate the building.

In case you haven’t heard of Faraday’s Christmas Lectures, they’re the UK’s nationally broadcasted “science special” featured at the end of the year and founded in 1825 by [Michael Faraday] himself. The goal of these Lectures is to introduce young people to some aspect from the sciences. We’ve seen giant Tetrises before, but not in a way that inspires such a young audience. We’re thrilled to see that hacking both in software (Python, LAN networks) and hardware (ZigBee, OpenWRT) made the cut for this year’s special. After all, why should MIT keep all the fun to themselves?

If the building-scale is just too big for your taste, why not have a go on your oscilloscope?

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